Tanning machinery

ABSTRACT

This invention relates to machines and processes for treating hides skins or the like, with liquids. Materials to be treated and the treating liquid are disposed in a processing chamber of a rotatable drum of a machine. A plurality of flat agitating members (so-called shelves) are secured in the chamber for rotation with the drum. Each of the shelves is disposed so that the axis of rotation of the drum intersects the plane in which the shelf lies with the axis making an acute angle with the projection of the axis on the plane so that in the process the material and a suitable quantity of treating liquid are disposed in the chamber and the drum is rotated about its axis with the axis inclined at such an angle that each shelf, as it enters the liquid, meets the surface of the liquid lying parallel with the surface.

United States Patent [1 1 oldsworth Oct. 21, 1975 TANNING MACHINERY [75] Inventor: Eric Holdsworth, Leeds, England [73] Assignee: Turner Machinery Limited, Leeds,

England 22 Filed: Aug. 21, 1974 21 Appl. No; 499,286

30 Foreign Application Priority Data 3,795,121 5/1974 Cressman 1. 69/30 Primary ExaminerAlfred R. Guest Attorney, Agent, or Firm-Aubrey C. Brine; Vincent A. White; Richard B. Megley [57] ABSTRACT This invention relates to machines and processes for treating hides skins or the like, with liquids. Materials to be treated and the treating liquid are disposed in a processing chamber of a rotatable drum of a machine. A plurality of flat agitating members (so-called shelves) are secured in the chamber for rotation with the drum. Each of the shelves is disposed so that the axis of rotation of the drum intersects the plane in which the shelf lies with the axis-making an acute angle with the projection of the axis on the plane so that in the process the material and a suitable quantity of treating liquid are disposed in the chamber and the drum is rotated about its axis with the axis inclined at such an angle that each shelf, as it enters the liquid, meets the surface of the liquid lying parallel with the surface.

14 Claims, 1 Drawing Figure US. Patent Oct. 21, 1975 TANNING MACHINERY BACKGROUND OF THE INVENTION In the manufacture of leather, hides skins or the like are treated with liquids for various purposes, for example to tan the leather. It has been proposed to effect such treatment in a machine comprising a drum having an opening at a front end portion thereof and a closed rear end portion, support means supporting the drum for rotation about an axis passing through the opening and the rear end portion, and means for tilting the drum so that the angle of the axis of rotation may be adjusted through a range of angles with respect to the horizontal. The drum has a processing chamber into which hides, skins or the like to be processed may be introduced through the opening; the machine further comprises, in the processing chamber, a plurality of flat or substantially flat, radial, agitating members (so-called shelves) secured for rotation with the drum.

In carrying out a process of treating hides skins or the like with liquid using such a machine, the processing liquid and material to be processed are introduced into the processing chamber; with the axis of rotation of the drum inclined at a suitable angle to the horizontal, the drum is rotated at a suitable speed and the shelves agitate the processing liquid and work the hides in the processing liquor.

While this machine and process perform in a fairly satisfactory manner, there is a tendency for the hides skins and the like to become entangled and to pack solidly together in a mass at the lower, rear end of the processing chamber thus restricting access of the liquid to those hides skins and the like in the centre of the mass so that they are not adequately exposed to the tanning liquid. Further, the liquid in the processing chamber is not adequately agitated and circulated: adequate agitation and circulation of the processing liquid is an important factor in many tanning processes. The hides skins or the like are sometimes not sufficiently thoroughly worked in the processing liquid, resulting in non-uniformity and poor quality of the processed hides skins or the like.

It is one of the various objects of the present invention to provide an improved machine for treating hides skins or the like with liquid, by the use of which improved quality of processed material may be achieved.

It is another of the various objects of the invention to provide an improved process of treating hides skins or the like with liquid by which improved quality of processed material is attained.

SUMMARY OF THE INVENTION The present invention provides a rotary drum mixing and processing machine comprising a drum having an opening at a front end portion thereof and a closed rear end portion, support means supporting the drum for rotation about an axis passing through the opening and the rear end portion, and means for tilting the drum so that the angle of the axis of rotation may be adjusted through a range of angles with respect to the horizontal, the drum having a processing chamber into which materials to be processed may be introduced through the opening, the machine comprising a plurality of flat, or substantially flat, agitating members in the processing chamber secured for rotation with the drum, each of the agitating members being so disposed that the axis of rotation intersects the plane in which the agitating member lies with the axis making an acute angle with the projection of the axis on the plane.

The present invention also provides a rotary drum mixing and processing machine comprising a drum having an opening at a front end portion thereof and a closed rear end portion, support means supporting the drum for rotation about an axis passing through the opening and the rear end portion, and means for tilting the drum so that the angle of the axis of rotation may be adjusted through a range of angles with respect to the horizontal, the drum having a processing chamber into which materials to be processed may be introduced through the opening, the machine comprising a plurality of agitating members in the processing chamber, secured for rotation with the drum, the construction and arrangement being such that the junction of each member with an inner surface of the drum lies in a plane which intersects the axis of rotation of the drum so that the projection of the axis on the plane makes an acute angle with the axis.

The present invention further provides a process for treating materials with liquid wherein liquid and materials to be treated are disposed in a processing chamber of a rotatable drum, in which chamber are disposed a plurality of flat or substantially flat agitating members each of the agitating members being so disposed that the axis of rotation of the drum intersects the plane in which the agitating member lies with the axis making an acute angle with the projection of the axis on the plane, and rotating the drum about the axis of rotation, the axis being inclined at an angle to the horizontal such that each agitating member, as it enters the liquid as the drum rotates, meets the surface of the liquid in the processing chamber lying parallel or substantially parallel with the surface.

In a preferred embodiment of the machine the agitating members terminate short of the rear of the processing chamber, suitably an axial distance of at least 25 percent of the axial length of the processing chamber from the rear of the processing chamber.

In a preferred embodiment of the machine the acute angle which the axis of rotation of the drum makes with the projection of the axis on the plane lies between 22% and 32%, more preferably between 25 and 30.

A preferred embodiment of the machine also comprises a drainage chamber in the drum conveniently at a rear end portion of the drum, separated from the processing chamber by means permitting flow of processing liquid but not material to be processed, between the processing chamber and the drainage chamber, the machine being so constructed and arranged that processing liquid can be introduced into and removed from the drainage chamber.

The means for tilting the drum of a preferred embodiment of the machine is arranged so that the axis of rotation of the drum is held at an angle of about 27 to the horizontal throughout the processing operation, the opening at the front end of the drum being upwardly directed; when the processing operation has been completed the means for tilting the drum is arranged so that the axis of rotation of the drum can be moved through such an angle that the opening from the front end portion of the drum is directed downwardly, thus to discharge the material being processed from the opening.

In a preferred embodiment of the machine the agitating members of the machine are arranged to be radial to the axis of rotation of the drum at a line across the member located in a region lying between half and three quarters of the length of the agitating members from the rearmost portion of the agitating members, corresponding to a region between 50 and 80 percent of the axial length of the processing chamber from the rear of the processing chamber.

In a preferred embodiment of the machine the front edge portions of the agitating members terminate an axial distance at least 7 percent of the axial length of the processing chamber from the opening and each agitating member extends a radial distance into the processing chamber at its region of maximum diameter not more than 20 percent of the maximum diameter.

In the preferred process the angle which the axis of rotation makes with its projection on the plane differs from the angleof inclination of the axis to the horizontal by not more than 5, preferably not more than 295; the axis of rotation is preferably inclined at an angle of about 27% to the horizontal.

DESCRIPTION OF THE DRAWINGS The above and other features of the invention will become more clear from the following description to be read with reference to the accompanying drawing which is a diagrammatic side view, with parts broken away of a machine for treating hides skins and the like which illustrates the invention by way of example.

DESCRIPTION OF THE ILLUSTRATIVE MACHINE The illustrative machine comprises an L-shaped frame having trunnions 6 carried in bearings 7 of base members 8 so that the frame can be tilted about an axis Y.

The illustrative machine further comprises a mixer drum supported by the frame 10 for rotation about an axis A; a trunnion 14 projects from a rear end portion of the drum 12 and is supported for rotation in bearings (not shown) carried by part of the frame 10 thus to support the rear end portion of the drum l2, and the drum 12 is additionally supported for rotation by rollers 16 carried by part of the frame, against which rollers 16 a runner ring 18 of the drum runs. Means (not shown) is provided for rotating the drum 12 about the axis A.

The drum 12 comprises a frusto-conical front end portion 20, joined to a cylindrical middle portion 22, the cylindrical middle portion 22 being joined to a frusto-conical rear portion 24; the cylindrical middle portion 22 has a diameter the same as that of the greatest diameter of the frusto-conical portions 20, 24. The rear portion 24 of the mixer drum 12 of the illustrative machine is closed by a flat rear wall 26 to which the trunnion 14 is secured. An annular support ring is secured to the side wall of the rear portion inside the drum 12; holes (not shown) are formed through the support ring 28 at intervals around it and studs 30 project forwardly from the support ring 28, the studs 30 being equally spaced around the ring. A perforated screen plate 32 has holes (not shown) in which the studs 30 are received, projecting forwardly beyond the screen plate 32, the screen plate 32 being secured to the support ring 28 by nuts 34 threaded on to the studs 30. A drainage chamber 36 is thus forrned at the rear end of the mixer drum 12, being bounded by the rear wall 26, the side wall of the rear portion 24 and the screen plate 32. Processing liquid may be supplied to or removed from the drainage chamber 36 through passage means (not shown) in the trunnion 14. The plate 32 is perforated to permit flow of processing liquid, introduced into the drainage chamber, between the drainage chamber 36 and a processing chamber 38 which is provided by the remainder of the interior of the drum, viz. that part of the drum bounded by the front end portion 20, the cylindrical portion 22 and the part of the rear portion 24 not given over to the drainage chamber 36.

Material to be processed, for example hides, may be introduced into the processing chamber through a circular opening 40 at the front end of the front end portion 20. The axes of the portions 20, 24 and cylindrical portion 22 are all coaxial with the axis A of rotation of the drum 12; the axis of rotation A also passes centrally through the trunnion 14 and through the circular opening 40. The diameter of the opening 40 is slightly less than half of the diameter of the cylindrical portion 22. The semi vertex angle of the frusto-conical portions 20, 24 is about 27%".

The illustrative machine further comprises a plurality of flat shelves 42 welded to the inner surface of the drum 12 in the processing chamber. The shelves 42 are equally spaced round the interior of the processing chamber and each of the shelves is inclined to the axis A of rotation of the drum 12. Each of the shelves 42 is so disposed that the axis A of rotation of the drum l2 intersects the plane in which the shelf 42 lies with the axis A making an acute angle P with the projection of the axis A on to the plane of the shelf 42. The angle P is 27 1?. Each of the shelves 42 terminates with its front edge just short of the opening 40. Each of the shelves 42 terminates short of the rear of the processing chamber viz. the screen plate 32; the rearmost edges of the shelves 42 coincide approximately with the region of the junction between the cylindrical portion 22 and the rear portion 24 of the drum and are spaced slightly over 25 percent of the total axial length of the processing chamber from the screen plate 32.

So that the shelves can be secured to the wall of the drum the profile of the outer edge of the shelves is rather complex. The width of the shelves 42 i.e. the spacing of the inner edges of the shelves from the wall of the drum is approximately constant over the whole of the length of the drum; however, at a front end portion of the shelves the inner edge is curved round until it meets the drum at an angle of (thus becoming the front edge of the shelf), while at a rear portion of the shelves the inner edge is straight and approaches the wall of the drum at an angle. The inner edges of the shelves are beaded so that the likelihood of damage being caused to the material processed is minimised.

Whereas the shelves 42 of the drum 12 are flat, the shelves 42 of a machine in accordance with the invention may not be flat throughout the whole of their width but may, for example, have a scooped inner edge portion, provided that the shelves are substantially flat along their length from front to rear of the drum.

In the operation of the illustrative machine in carrying out the illustrative process the frame 10 is swung about the axis on which it is supported by means of a suitable motor 45 to tilt the drum 12 so that the axis A is inclined at a suitable angle to the horizontal. When the axis of rotation is inclined at an angle of about 27%; to the horizontal and the drum 12 (in which are disposed the hides and a suitable quantity of processing liquid) is rotated in the correct sense, each shelf, as it enters the processing liquid in carrying out the illustrative process, meets the surface of said liquid lying substantially parallel to the surface; this ensures efficient agitation of the processing liquid. This angle of 27% is also sufficient to not allow overflow of the liquid from the opening 40 when the quantity of liquid is such that the shelves meet the liquid surface as described. As each shelf leaves the processing liquid, on the other hand, it has a fierce pitch towards the rear of the drum, thereby tending to cause processing liquid to be propelled to the rear of the drum, namely into that region of the processing chamber between the screen plate 32 and the ends of the shelves 42. Thus, in the operation of the illustrative machine, as a shelf leaves the processing liquid, the liquid and any hides in the vicinity of said shelf are propelled from the front end of the drum rearwardly into the said region of the processing chamber and are then caused to swirl across the screen plate 32; immediately following the action of the shelf leaving the liquid, the next shelf 42 enters the liquid, and thus the liquid and hides are urged forwardly from said region towards the opening 40, and the liquid and hides are then caused to swirl across the front of the drum between the opening and the forward ends of the shelves. This cycle is of course continuous in the operation of the illustrative machine in carrying out the illustrative method.

It will thus be appreciated that, in addition to the radial tumbling of the hides, a circulating motion is also imparted thereto in the operation of the illustrative machine, this circulating motion being achieved by arranging the shelves at an angle to the axis of rotation of the drum and also by the provision of shelves which do not extend along the length of the drum, so that one or more free regions can be provided in which hides are not directly contacted by the shelves.

By providing this facility for circulating motion of the hides, there is little or no tendency for hides to pack against the screen plate. in this way, processing liquid is able to flow freely between the drainage chamber and the processing chamber, and at the same time the processing liquid has a greater degree of access to the hides being processed, thereby improving the efficiency of operation of the illustrative machine.

Having described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A rotary drum mixing and processing machine comprising a drum having an opening at a front end portion thereof and a closed rear end portion, support means supporting the drum for rotation about an axis passing through the opening and the rear end portion, and means for tilting the drum so that the angle of the axis of rotation may be adjusted through a range of angles with respect to the horizontal, the drum having wall structure forming a processing chamber of substantially circular cross section into which materials to be processed may be introduced through the opening, said chamber being symmetrical with said axis of rotation, the machine further comprising a plurality of flat, planar, agitating members disposed in the processing chamber and secured for rotation with the drum, each of said agitating members defining a plane which, upon intersecting said wall structure, forms a line which forms an acute angle with any line produced by the intersection of a radial plane intersecting said agitating members and emanating from said axis of rotation with said wall structure.

2. A machine according to claim 1 wherein an outer edge portion of each member is secured to an internal surface of the drum.

3. A machine according to claim 1 wherein the agitating members terminate short of the rear of the processing chamber.

4. A machine according to claim 3 wherein the agitating members terminate an axial distance of at least 25 percent of the axial length of the processing chamber from the rear of the processing chamber.

5. A machine according to claim 1 wherein the means for tilting the drum is arranged to maintain the axis of rotation of the drum at such an angle to the horizontal during operation of the drum that each agitating member, as it enters the liquid as the drum rotates, meets the surface of the processing liquor in the processing chamber, lying parallel or substantially parallel with the surface of the liquid.

6. A machine according to claim I wherein the means for tilting the drum maintains the axis of rotation of the drum during the processing operation at an angle of about 27% to the horizontal.

7. A machine according to claim 1 wherein the acute angle which the axis makes with the projection of the axis on the plane lies between about 22% and about 32 8. A machine according to claim 1 wherein a line on an agitating member is radial to the axis of rotation of the drum at a region lying between half and three quarters of the length of the agitating members from the rearmost portion of the agitating member.

9. A machine according to claim 1 wherein a line on an agitating member lies radially to the axis of rotation of the drum at a region between 50 percent and percent of the axial length of the processing chamber from the rear of the processing chamber.

10. A machine according to claim 1 wherein front portions of the agitating members terminate an axial distance at least 7 percent of the axial length of the processing chamber from the opening.

11. A machine according to claim 1 wherein each agitating member extends a radial distance into the processing chamber at its region of maximum diameter not more than 20 percent of the maximum diameter.

12. A process for treating materials with liquid wherein liquid and materials to be treated are disposed in a processing chamber of a rotatable drum which includes the steps of providing a plurality of flat planar agitating members in said chamber, each of the agitating members being so disposed that the axis of rotation of the drum intersects the plane in which the agitating member lies with the axis making an acute angle with the projection of the axis on the plane, tilting the drum to a position wherein the axis is inclined at an angle to the horizontal such that each agitating member, as it enters the liquid as the drum rotates in one direction, meets the surface of the liquid in the processing chamber lying parallel or substantially parallel with the surface and rotating the drum about the axis of rotation in the said direction with the agitating member entering the liquid substantially parallel with the surface and leaving the liquid at an acute angle with the liquid surface.

13. A process according to claim 12 wherein the angle which the axis makes with the projection of the axis on the plane differs from the angle of inclination of the axis to the horizontal by not more than about 5.

14. A process according to claim 12 wherein the angle of inclination of the axis to the horizontal is about 27%. 

1. A rotary drum mixing and processing machine comprising a drum having an opening at a front end portion thereof and a closed rear end portion, support means supporting the drum for rotation about an axis passing through the opening and the rear end portion, and means for tilting the drum so that the angle of the axis of rotation may be adjusted through a range of angles with respect to the horizontal, the drum having wall structure forming a processing chamber of substantially circular cross section into which materials to be processed may be introduced through the opening, said chamber being symmetrical with said axis of rotation, the machine further comprising a plurality of flat, planar, agitating members disposed in the processing chamber and secured for rotation with the drum, each of said agitating members defining a plane which, upon intersecting said wall structure, forms a line which forms an acute angle with any line produced by the intersection of a radial plane intersecting said agitating members and emanating from said axis of rotation with said wall structure.
 2. A machine according to claim 1 wherein an outer edge portion of each member is secured to an internal surface of the drum.
 3. A machine according to claim 1 wherein the agitating members terminate short of the rear of the processing chamber.
 4. A machine according to claim 3 wherein the agitating members terminate an axial distance of at least 25 percent of the axial length of the processing chamber from the rear of the processing chamber.
 5. A machine according to claim 1 wherein the means for tilting the drum is arranged to maintain the axis of rotation of the drum at such an angle to the horizontal during operation of the drum that each agitating member, as it enters the liquid as the drum rotates, meets the surface of the processing liquor in the processing chamber, lying parallel or substantially parallel with the surface of the liquid.
 6. A machine according to claim 1 wherein the means for tilting the drum maintains the axis of rotation of the drum during the processing operation at an angle of about 27 1/2 * to the horizontal.
 7. A machine according to claim 1 wherein the acute angle which the axis makes with the projection of the axis on the plane lies between about 22 1/2 * and about 32 1/2 *.
 8. A machine according to claim 1 wherein a line on an agitating member is radial to the axis of rotation of the drum at a region lying between half and three quarters of the length of the agitating members from the rearmost portion of the agitating member.
 9. A machine according to claim 1 wherein a line on an agitating member lies radially to the axis of rotation of the drum at a region between 50 percent and 80 percent of the axial length of the processing chamber from the rear of the processing chamber.
 10. A machine according to claim 1 wherein front portions of the agitating members terminate an axial distance at least 7 percent of the axial length of the processing chamber from the opening.
 11. A machine according to claim 1 wherein each agitating member extends a radial distance into the processing chamber at its region of maximum diameter not more than 20 percent of the maximum diameter.
 12. A process for treating materials with liquid wherein liquid and materials to be treated are disposed in a processing chamber of a rotatable drum which includes the steps of providing a plurality of flat planar agitating members in said chamber, each of the agitating members being so disposed that the axis of rotation of the drum intersects the plane in which the agitating member lies with the axis making an acute angle with the projection of the axis on the plane, tilting the drum to a position wherein the axis is inclined at an angle to the horizontal such that each agitating member, as it enters the liquid as the drum rotates in one direction, meets the surface of the liquid in the processing chamber lying parallel or substantially parallel with the surface and rotating the drum about the axis of rotation in the said direction with the agitating member entering the liquid substantially parallel with the surface and leaving the liquid at an acute angle with the liquid surface.
 13. A process according to claim 12 wherein the angle which the axis makes with the projection of the axis on the plane differs from the angle of inclination of the axis to the horizontal by not more than about 5*.
 14. A process according to claim 12 wherein the angle of inclination of the axis to the horizontal is about 27 1/2 *. 